Surface treatment composition, method of surface treatment, substrate and article

ABSTRACT

The object of the present invention is to provide a surface treatment composition having excellent storage stability and waterdrop rolling property. 
     The present invention provides a surface treatment composition containing a partial hydrolysate of a fluorine-containing reactive silane such as C 8 F 17 CH 2 CH 2 Si(OCH 3 ) 3  having a molecular weight of M measured by GPC, wherein the proportion of molecules with molecular weights of from 300 to at most 2M in the partial hydrolysate is less than 70%, and the proportion of molecules with molecular weights of from 6M to 100000 in the partial hydrolysate is less than 10%. 
     The present invention also provides a method of surface treatment of glass with the surface treatment composition. 
     The present invention also provides a substrate treated with the surface treatment composition. 
     The present invention also provides an article incorporating the substrate such as a transport equipment.

TECHNICAL FIELD

The present invention relates to a surface treatment composition whichimparts excellent water repellency and waterdrop rolling property to thesurface of a substrate, a substrate treated with the surface treatmentcomposition and a method for its production.

BACKGROUND ART

Glass, plastic, ceramic and metal substrates and substrates havingtreated surface layers are used in various fields. A problem with thesesubstrates is the adverse effects of dirt on their surfaces such aswater and dust.

For example, for transports such as electric railcars, automobiles,ships and aircrafts, it is desirable to keep the exterior parts such asouter panels, windowpanes, mirrors and surface panels of display signs,the interior parts such as surface panels of measuring instruments andother equipments clean. However, deposition of raindrops, dust and soilor water condensation due to the influence of the atmospheric humidityand temperature on the surfaces of transport equipments not only cancause a problem of damage to their appearances but also causes anuncomfortable impression and sanitary problems in a case of a directlyvisible or touchable substrate and impair the essential functions of thetransport equipments. Especially, in cases of transport equipmentsrequired to be transparent or see-through such as windowpanes andmirrors, reduction in transparency and the see-through property isproblematic.

On the other hand, removal of dust, soil or water by wiping or with awiper can cause a problem of fine scratches on the substrate surface.Further, foreign particles accompanying dust, soil or water canaggravate the scratches. Furthermore, water deposited on a glass surfacecan erode the surface by eluting glass components and causes aphenomenon called “scorching”. However, strong abrasion for removal ofscorch marks can problematically lead to formation of fineirregularities. If severely scorched glass or glass having fineirregularities on the surface is used for a see-through part, it canruin the essential function of the see-through part, causing terriblelight scattering on the surface. Therefore, it is difficult to securevisibility.

In addition, dust, soil and water cause problems of promotion of damage,fouling, discoloration and corrosion on the surfaces of transportequipments and problems of induction of change in their electricalproperties, mechanical properties and optical properties. These problemsalso exist in the fields of building materials and decorations andequipments for electric and electronic appliances.

Surface treatment of a substrate with a composition containing a partialhydrolysate of a fluorine-containing reactive silane as an essentialcomponent with a view to imparting the property of repelling waterdropsand removing their adverse effects (hereinafter referred to as waterrepellency), the antifouling property and low reflectivity, can beaccomplished by known methods disclosed in the following publications.

JP-A-50-126033, JP-A-59-115840, JP-A-61-40845, JP-A-61-241143,JP-A-61-215235, JP-A-1-95181, JP-A-2-248480, JP-A-2-115801,JP-A-4-341379, JP-A-4-342444, JP-A-4-328188, JP-A-5-279499 andJP-A-1-170486.

These publications disclose partial hydrolysis of a fluorine-containingreactive silane with an acid such as hydrochloric acid, sulfuric acid,nitric acid, phosphoric acid, acetic acid and a sulfonic acid.

However, conventional compositions have problems of uneven application,unsatisfactory adhesiveness to a substrate and the unenduringantifouling property. Besides, treatment of a substrate incorporated inan article or in or after use with a water and oil repellent has to bedone at ordinary temperature. For example, it is economicallydisadvantageous to detach the front windshield of an automobile which isalready on sale for its treatment. Further, it is out of the question totreat the front windshield without detaching it and then bake the wholeautomobile. Because it is impossible to prepare a composition afresheach time treatment is done, such a composition is required to befunctional over a long time and have good storage stability.

However, conventional compositions have limited applications due toproblems of their low storage stability and difference in theirpost-storage performance. Conventional compositions proposed so far donot have the property of draining waterdrops on the surface of asubstrate (hereinafter referred to as the waterdrop rolling property) aswell as the above-mentioned properties and have a problem that when theyare applied to transport equipments, visibility can not be secured.

DISCLOSURE OF THE INVENTION

The present inventors have studied to overcome the above-mentioneddrawbacks of conventional compositions. As a result, they have found outthat the above-mentioned drawbacks are attributed to inappropriatelyselected partial hydrolysis conditions which lead to a high proportionof molecules with low- or high-molecular weights in the resultingpartial hydrolysate and a composition having large acid and watercontents.

They have also found out that a surface treatment agent containing aspecific partial hydrolysate is excellent in water repellency,antifouling property, waterdrop rolling property, adhesiveness(durability), abrasion resistance, chemical resistance and storagestability.

Namely, the present invention provides a surface treatment compositioncontaining a partial hydrolysate of a fluorine-containing reactivesilane represented by the following formula 1 as an essential component,which the proportion (T₁) of molecules with molecular weights of at most2 M calculated from the following formula A in the partial hydrolysateis less than 70%, and the proportion (T₂) of molecules with molecularweights of at least 6 M calculated from the following formula B in thepartial Th hydrolysate is less than 10%, wherein M is the molecularweight of the fluorine-containing reactive silane measured by gelpermeation chromatography:

[Ka2]

(R^(f)—Q—) a (R¹)_(b)Si (X¹)₄−a−b  formula 1

wherein

R^(f): a monovalent fluorine-containing C₁₋₃₀ organic group,

Q: a single bond or a bivalent linking group,

R¹: a hydrogen atom or a monovalent C₁₋₁₆ organic group,

a: 1 or 2,

b: 0 or 1, and (a+b) is 1 or 2, and

X¹: a hydrolyzable group,

[Su3]

T ₁(%)=[W ₂ /W ₁]×100  formula A

T ₂(%)=[W ₃ /W ₁]×100  formula B

wherein

W₁: the total peak area within a molecular weight range of from 300 to100000 on a gel permeation chromatogram of the partial hydrolysate ofthe fluorine-containing reactive silane,

W₂: the total peak area within a molecular weight range of from 300 to 2M on a gel permeation chromatogram of the partial hydrolysate of thefluorine-containing reactive silane, and

W₃: the total peak area within a molecular weight range of from 6 M to100000 on a gel permeation chromatogram of the partial hydrolysate ofthe fluorine-containing reactive silane.

BEST MODE FOR CARRYING OUT THE INVENTION

R¹ in the fluorine-containing reactive silane (hereinafter referred toas compound 1) is a hydrogen atom or a monovalent C₁₋₁₆ organic group.An organic group means a carbon-containing group, and the monovalentorganic group preferably has from 1 to 8 carbon atoms.

The monovalent C₁₋₁₆ organic group may be an organic group havinghalogen atoms, functional groups or linking groups and is preferably amonovalent hydrocarbon group or a monovalent organic group havinghalogen atom(s) which may have functional group(s) or linking group(s).

The monovalent hydrocarbon group may be a monovalent aliphatichydrocarbon group or a monovalent aromatic hydrocarbon group, preferablyan aliphatic hydrocarbon group. As the monovalent aliphatic hydrocarbongroup, an alkyl group, an alkenyl group or a cycloalkyl group,preferably an alkyl group, particularly preferably an alkyl group havingat most 4 carbon atoms such as a methyl group, an ethyl group, a propylgroup or a butyl group may be mentioned. As the aromatic hydrocarbongroup, an aryl group is preferable.

A monovalent halogenated organic group means a monovalent organic grouphaving halogen atom(s) substituting for at least one hydrogen atom. As amhalogen atom, a chlorine atom or a fluorine atom, particularly afluorine atom, is preferable. The monovalent halogenated organic groupis preferably a monovalent halogenated hydrocarbon group, particularly ahalogenated alkyl group such as a chloroalkyl group, a fluoroalkyl groupor a chlorofluoroalkyl group.

The monovalent halogenated organic group is preferably a monovalentpolyfluoro-organic group having fluorine substituting for at least twohydrogen atoms in an organic group.

R^(f) in compound 1 is a monovalent fluorine-containing C₁₋₁₆ organicgroup.

A monovalent fluorine-containing organic group means such a monovalentorganic group as mentioned above in which at least one hydrogen atom issubstituted by fluorine atom(s). R^(f) may contain, in addition tofluorine, other halogen atom(s) or functional group(s) or may have alinking group between carbon-carbon bonds. The R^(f) group preferablyhas from 3 to 18 carbon atoms, especially from 4 to 16 carbon atoms.

The monovalent polyfluoro-organic group is preferably a monovalentpolyfluorohydrocarbon group, especially a polyfluoroalkyl group. Apolyfluoroalkyl group means a an alkyl group in which at least twohydrogen atoms have been substituted by fluorine atoms. Hereafter apolyfluoroalkyl group will be expressed as “an R^(F) group”.

The R^(F) group may have a linear or branched structure, preferably alinear structure. In the case of a branched structure, a branchpreferably has at most 4 carbon atoms. The proportion of fluorine atomsin the R_(F) group is preferably at least 60%, particularly at least80%, when expressed as (the number of fluorine atoms in the R^(F)group)/(the number of hydrogen atoms in the corresponding alkyl grouphaving the same carbon atoms as the R^(F) group).

The R^(F) group may contain an ethereal oxygen atom (—O—) or athioethereal sulfur atom (—S—). For example, a polyfluorooxalkyl group,a polyfluorothioalkyl group or a group containing such a group may bementioned. As the polyfluorooxalkyl group, a group having apolyfluoroethyleneoxy moiety or a polyfluoropropyleneoxy moiety or agroup having a polyfluoroethyloxy moiety or a polyfluoropropyloxy moietymay be mentioned. As the polyfluorothioalkyl group, a group having apolyfluoroethylenethio moiety or a polyfluoropropylenethio moiety or agroup having a polyfluoroethylthio moiety or a polyfluoropropylthiomoiety may be mentioned. The R^(F) group may have a functional group.

The group R^(F) is preferably a perfluoroalkyl group which correspondsto such an R^(F) group as mentioned above in which all the hydrogenatoms have been replaced by fluorine atoms or a group containing such aperfluoroalkyl group or a perfluoroalkylene group as a part of itsstructure. The perfluoroalkyl group in the R^(F) group has preferablyfrom 3 to 18 carbon atoms, and the perfluoroalkylene group in the R^(F)group has preferably from 2 to 18 carbon atoms. The R^(F) group ispreferably a perfluoroalkyl group.

Q is a single bond or a bivalent linking group, preferably a bivalentlinking group. When Q is a single bond, the formula 1 means that R_(F)is directly bonded to Si. The carbon atom in the R_(F) group which isdirectly bonded to a bivalent linking group is preferably bonded to atleast one fluorine atoms. The bivalent linking group as Q is selectedfrom known or common bivalent linking groups and exemplified in theafter-mentioned specific examples of compound 1. Q is preferablyalkylene group, particularly —(CH₂)_(e)— (wherein e is an integer offrom 1 to 6, preferably 2 or 3). R^(f) —Q— in the formula 1 ispreferably a monovalent organic group represented byCF₃(CF₂)_(d)(CH₂)_(e)— (wherein d is an integer of from 2 to 17, and eis the same as defined above).

X¹ in compound 1 is a hydrolyzable group such as —OR³ (wherein R³ is aC₁₋₆ alkyl group), an acyloxy group, an alkoxy-substituted alkoxy group,a halogen atom, an isocyanato group, aminoxy group, an amido group, anacid amido group, a ketoxymate group, a hydroxyl group, a mercaptogroup, an epoxy group or a glycidyl group. According to the presentinvention, the hydrolyzable group includes an isocyanato group. R³ in—OR³ is preferably a methoxy group or an ethoxy group.

X¹ in compound 1 is preferably —OR³ or a halogen atom, particularly—OR³. The halogen atom as X¹ is preferably a chlorine atom, and thealkoxy group as X¹ is preferably an alkoxy group having at most 4 carbonatoms. The number of X¹ in compound 1 is 2 or 3, preferably 3. Namely,(a+b) is 1 or 2, preferably 1. a is preferably 1, and b is preferably 0.

As compound 1 in the present invention, the following compounds may bementioned. In the following formulae, R^(f), Q, R¹ and X¹ are the sameas defined above, and m is an integer of at least 1.

[Ka 3]

(A-1): R^(f)C₂H₄Si(X¹)₃

(A-3): (R^(f)C₂H₄)₂Si(X¹)₂ (A-4): R^(f)C₂H4NH(CH₂)₂Si (X¹)₃

(A-5): R^(f)CONHC₃H₆Si(X¹)₃

(A-7): R^(f)CONHC₂H₄NHC₃H₆Si(X¹)₃

(A-9): R^(f)CON(CH₃)C₂H₄CON(CH₃)Si(X¹)₃

(A-11): R^(f)C₂H₄OCO(CH₂)₂S(CH₂)₃Si(X¹)₃

(A-13): R^(f)C₂H₄OCONH(CH₂)₃Si(X¹)₃

The compound of the present invention contains a partial hydrolysate ofcompound 1 as an essential component. The partial hydrolysate ofcompound 1 is the product of partial hydrolysis of compound 1 which maycontain a thoroughly hydrolyzed fraction. Compound 1 itself does notfall under the definition of the partial hydrolysate.

The partial hydrolysate of compound 1 may be the product of partialhydrolysis of more than one species of compound 1. The partialhydrolysate of compound 1 in the present invention may be the product ofco-hydrolysis of at least one species of compound 1 and at least onespecies of compound 2 mentioned below. In the following formula 2,R^(f), Q, R¹ and X¹ are the same as defined above, and R² is a hydrogenatom or a C₁₋₁₆ organic group. Preferable embodiments of R are the sameas those of R¹.

[Ka4]

(R^(f)—Q—)(R¹)(R²)Si(X¹)  formula 2

In the present invention, the partial hydrolysate is preferably theproduct of hydrolysis of at least one species of compound 1 and isusually a mixture of at least two product components. A coating obtainedby applying the composition of the present invention which contains thepartial hydrolysate is excellent in the waterdrop rolling property,durability and workability.

In the present invention, a crude reaction liquid obtained after partialhydrolysis is preferably used as the composition of the presentinvention by itself or after addition necessary additives.

For synthesis of the partial hydrolysate of compound 1, known hydrolyticmethods are basically applicable. However, because the partialhydrolysate in the present invention is characterized by a specificmolecular weight distribution, the reaction conditions have to bestrictly controlled. Reaction conditions such as the species and amountof compound 1, the amount of water, the amounts and species of the otherreagents, the reaction procedure, the reaction time and temperaturegovern the molecular weight distribution.

Compound 1 preferably has the group —OR³ as X¹ in view of easiness incontrol of the molecular weight distribution of the partial hydrolysate.Compound 1 wherein X¹ is the group —OR³ is represented by the followingformula 1′.

[Ka5]

(R^(f)—Q—)_(a)(R¹)_(b)Si(—OR³)_(4−a−b)  formula 1′

In the formula 1′, R^(f), Q, R¹, a, b and R³ are the same as definedabove, and their preferable embodiments are the same as mentioned above.In the present invention, compounds wherein a is 2, and b is 0 arepreferable.

The compound represented by the formula 1′ [hereinafter referred to ascompound 1′] is characterized in that it hydrolyzes slower than compound1 wherein X¹ is a halogen atom and is therefore preferably because itdoes not generate precipitates upon abrupt hydrolysis and facilitatesmolecular weight control.

Further, the amount (moles) of water used for the hydrolysis ispreferably so adjusted that the H value calculated from the followingformula C is from 2 to 7.

[Su4]

H=[the total number of moles of water used for the hydrolysis]/[thetotal number of moles of X1 in compound 1 used for thehydrolysis]  formula C

If the H value is less than 2, the hydrolysis does not proceedsufficiently and yields a partial hydrolysate with a large low-molecularweight fraction, and the waterdrop rolling property and coatingdurability can be insufficient. On the other hand, if the H valueexceeds 7, the hydrolysis proceeds too fast and yields a partialhydrolysate with a large high-molecular weight fraction, and theworkability and coating durability can be insufficient.

For partial hydrolysis of compound 1 in the present invention, thefollowing basic methods a to c are preferable.

[Method a] Mixing of compound 1 and water.

[Method b] Mixing of compound 1 and water in the presence of an acid.

[Method c] Mixing of compound 1 and water in the presence of an alkali.

In the present invention, method b is preferable in view of easiness ofmolecular weight control. The acid in method b is preferably sulfuricacid, hydrochloric acid, nitric acid, methanesulfonic acid, phosphoricacid or acetic acid. As the acid in method b, nitric acid isparticularly preferable in view of workability, easiness in handling andphysical properties of coatings. With the other acids, the followingdefects are conceivable. Hydrochloric acid and sulfuric acid can affectsurfaces to be treated and cause inconveniences in handling of theresulting composition. Sulfuric acid can decompose the resulting partialhydrolysate. Methanesulfonic acid, phosphoric acid and acetic acid canlead to inefficient production of the partial hydrolysate because oftheir weak acidities.

When nitric acid is used for the hydrolysis, the amount of nitric acidin mole is preferably from 0.001 to 0.1 time that of compound 1. If theamount of nitric acid is too small, the reaction rate is likely to betoo low, while if the amount of nitric acid is too large, the reactionrate is likely to be too high for molecular weight.

In any of methods a to c, the hydrolysis is preferably carried out inthe presence of an organic solvent. When an organic solvent is used, itis preferred to firstly dissolve compound 1 in the organic solvent. Theamount of an organic solvent used for the hydrolysis is preferably soadjusted that the composition contains compound 1 in an amount of 0.1 wt% to 10 wt % in view of economy, coating thickness, control of thehydrolysis and workability.

Specific examples of the organic solvent include alcohol solvents,cellosolve solvents, carbitol solvents, acetate solvents, ketonesolvents, ester solvents and halogenated hydrocarbon solvents. Alcoholsolvents, especially lower alcohol solvents such as ethanol or isopropylalcohol, are preferable. One or more organic solvents may be used. It ispreferred to appropriately select an organic solvent in view of thesolvent resistance of the substrate, the size of the substrate, thevaporization rate of the solvent and economy.

The reaction time of the partial hydrolysis is preferably from 3 to 250hours, and the reaction temperature is preferably from 15 to 80° C.

Method b in which nitric acid is used as the acid may be exemplified bythe following specific methods b¹ and b², and method b² is particularlypreferable.

[Method b ] Addition of predetermined amounts of nitric acid and waterto compound 1.

[Method b ] Addition of a previously prepared aqueous nitric acidsolution to compound 1.

In method b², an aqueous nitric acid solution may be added to compound 1at a time or gradually, preferably gradually, particularly preferablydropwise.

The partial hydrolysate in the present invention has to satisfy aspecific molecular weight distribution upon molecular weight measurementby gel permeation chromatography (hereinafter referred to as GPC) over amolecular weight range of 300 to 100000. A molecular weight measured byGPC is not strictly the same as the total atomic weight of therespective elements.

A molecular weight measured by GPC is based on that of a known substance(a standard). In the present invention, a molecular weight is based onthat of polystyrene. In the present invention, molecular weights arepreferably measured by the following method. Namely, polystyrene with aknown molecular weight within the range of from 300 to 100000 ischromatographed to give a GPC chromatogram. Then, the detection time andmolecular weight of the polystyrene on the chromatogram are correlatedto give a calibration curve. The detection time of a partial hydrolysateof compound 1 is converted into its molecular weight on the calibrationcurve.

The surface treatment agent of the present invention is substantiallyfree from partial hydrolysate molecules of molecular weights of morethan 100000, because partial hydrolysate molecules of molecular weightshigher than 100000 impair the performance of the composition as asurface treatment agent by forming precipitates in the composition orcausing gelation of the composition.

The proportion of the partial hydrolysate in the composition isdetermined as follows. Namely, the molecular weight, M, of compound 1 isdetermined from its GPC chromatogram. Compound 1 in the presentinvention preferably has a molecular weight (M) of from 300 to 1000,particularly from 400 to 800. When more than one species of compound 1are used for partial hydrolysis, the highest of their molecular weightsmeasured by GPC is defined as M.

Then, the proportion (T₁ value) of molecules with molecular weights offrom 300 to 2 M in the partial hydrolysate is determined from the areasof the peaks on a GPC chromatogram of the hydrolysate. The T₁ value canbe calculated from the following formula A.

[Su5]

T₁ (%)=[W ₂ /W ₁]×100  formula A

wherein

W₁: the total peak area within a molecular weight range of from 300 to100000 on a GPC chromatogram of the partial hydrolysate of thefluorine-containing reactive silane, and

W₂: the total peak area within a molecular weight range of from 300 to 2M on a GPC chromatogram of the partial hydrolysate of thefluorine-containing reactive silane.

In the present invention, the T₁ value is less than 70%, preferably from10 to 60%. A T₁ value of less than 70% secures a good waterdrop rollingproperty and excellent durability.

The presence of a large amount of partial hydrolysate molecules withhigh molecular weights in the composition is undesirable. Especially,molecules of molecular wrights of 6 M or higher are undesirable becauseincrease of their proportion leads to gelation of the composition. Theproportion (T₂ value) of molecules with molecular weights of from 6 M to100000 in the partial hydrolysate can be calculated from the followingformula B.

[Su6]

T₂ (%)=[W ₃ /W ₁]×100  formula B

wherein

W₁: the total peak area within a molecular weight range of from 300 to100000 on a GPC chromatogram of the partial hydrolysate of thefluorine-containing reactive silane, and

W₃: the total peak area within a molecular weight range of from 6 M to100000 on a GPC chromatogram of the partial hydrolysate of thefluorine-containing reactive silane.

The T₂ value is preferably less than 10%, particularly from 0 to 5%.

If the T₂ value is not less than 10%, namely if the proportion ofmolecules with molecular weights of at least 6 M in the partialhydrolysate of the fluorine-containing reactive silane compound is high,the workability during surface treatment is terribly poor, and thedurability of the resulting coating can be poor.

Further, the proportion of molecules of molecular weights of from 2 to 6M in the partial hydrolysate of compound 1 is preferably from 30 to100%, particularly from 40 to 90%, when expressed as the proportion ofthe total peak area within a molecular weight range of from 2 M to 6 Mon a GPC chromatogram of the hydrolysate to W₁. Control of thisproportion is preferable to secure an excellent waterdrop rollingproperty, good workability and coating durability. The amount ofcompound 1 in the composition is preferably controlled to at most 10 wt%.

Further, the weight-average mean molecular weight of the partialhydrolysate of compound 1 is preferably from 1.6 M to 3.5 M,particularly from 1.8 M to 2.8 M. In general, the composition of thepresent invention preferably contains an organic solvent as well as thepartial hydrolysate of compound 1. The organic solvent is usually theone used for the hydrolysis, but if necessary, another organic solventmay be added. The composition of the present invention will be describedbelow as containing an organic solvent.

The composition contains the partial hydrolysate of compound 1preferably in an amount of from 0.1 to 10 wt % and an organic solvent insuch an amount that the final concentration of compound 1 is from 0.1 to10 wt %. Further, it is preferred to use an organic solvent with aboiling point suitable for the treating area in view of the applicationconditions for the composition of the present invention, and an organicsolvent having a boiling point of from 60 to 200° C., particularly from70 to 150° C. is preferable.

The water and oil repellent composition of the present invention usuallyfurther contains the water used for the hydrolysis. The amount of waterin the composition is an important factor for the storage stability ofthe composition and preferably from 0.5 to 3 wt %. The presence of morethan 3 wt % of water can not only make the composition less stable bycausing a change in the liquid composition during storage but also makethe composition less workable by retarding drying of the composition.

The amount of nitrate ion in the composition is also j important inrespect of storage stability and preferably from 0.005 to 0.1 wt %. Thepresence of more than 0.1 wt % of nitrate ion can make the compositionless stable by causing a change in the liquid composition duringstorage.

The water and oil repellent composition of the present invention maycontain additives which meet particular purposes. As additives,ultrafine particles of metals and metal oxides, resins, antioxidants,surfactants, ultraviolet absorbers, colorants such as dyes and pigmentsand electrical conductors may be mentioned. It is preferred to selectadditives by considering the compatibility and reactivity with otherconstituents. The amount of additives in the composition is preferablyless than 20 wt %. 20 wt % or more of additives can lower the waterdroprolling property, durability and workability.

The composition of the present invention imparts excellent propertiessuch as water repellency, an antifouling property and a water drippingproperty to the surface of a substrate when applied to the surface. Asthe substrate, substrates made of metals, ceramics, plastics, glass andother inorganic materials, substrates made of organic materials andsubstrates made of combinations of at least two selected from inorganicand organic materials (composites or laminates) may be mentioned.

The substrate may also have a surface made of a different material andmay have a coated surface like a coated metal plate or a surfacetreatment layer like a surface-treated glass. The shape of the substratemay be planar or have a totally or partly curved surface.

The composition of the present invention can be applied by commonmethods. It is noteworthy that the composition of the present inventioncan be applied to a substrate incorporated in another article or asubstrate in or after use because it can exert excellent performanceeven applied at ordinary temperature.

The substrate is preferred to have functional groups which can reactwith X¹ on the surface. A substrate having functional groups on thesurface can make the effects of the composition last longer. As thefunctional groups, hydroxyl groups, isocyanato groups, sulfonic groups,amino groups and carboxyl groups may be mentioned, and hydroxyl groupsare preferable. As a substrate having hydroxyl groups on the surface, asubstrate having many hydroxyl groups on the surface, particularly aglass substrate, is preferable.

On the other hand, when the substrate has no functional groups on thesurface or when the number of functional groups on the surface of thesubstrate is insufficient, it is preferred to subject the substrate topretreatment.

Examples of pretreatment include sandblast treatment, abrasive treatmentwith cerium oxide particles or the like, acidic treatment withhydrofluoric acid or the like, alkaline treatment with sodium hydroxideor the like, discharge treatment by corona discharge or the like andformation of a film having functional groups. For formation of a filmhaving functional groups, a glass film may be formed by a sol-gelmethod.

The above-mentioned pretreatment methods are classified according totheir main purposes as those which increase the number of availablefunctional groups by cleansing the substrate surface (d¹ methods) andthose which actually increase the number of hydroxyl groups on thesubstrate surface (d² methods).

Among the d¹ methods, abrasive cleansing using abrasive particles ispreferable. As abrasive particles, particles of cerium oxide, alumina,silica, zirconia, diamond or calcium carbonate are preferable.

Among the d² methods, the sol-gel method and formation of a film derivedfrom a hydrolyzable silane other than compound 1 on the substratesurface are preferable. As the hydrolyzable silane, a compoundrepresented by the following formula 3 (hereinafter referred to ascompound 3) and/or a partial hydrolysate of compound 3 is preferable.

[Ka6]

(R⁴)_(d)(R⁵)_(e)(R⁶)_(f)Si(X²)_(4−d−e−f)  formula 3

wherein

R³, R⁴ and R⁵: independently a monovalent fluorine-free C₁₋₁₆ organicgroup,

d, e and f: independently 0, 1, 2 or 3, provided that (d+e+f) is 0, 1, 2or 3,

X²: a hydrolyzable group.

R⁴, R⁵ and R⁶ are preferably organic groups having a vinyl group, anepoxy group, a glycidyl group, a hydroxyl group, an amino group, anisocyanato group or a mercapto group as a functional group.

X² is preferably the hydrolyzable group exemplified in the explanationof compound 1 and is preferably an alkoxy group or an isocyanato group.

Specific examples of formula 3 include the following compounds.

Tetraalkoxysilanes such as tetramethoxysilane, tetraethoxysilane,tetra(n-propoxy)silane, tetra(i-propoxy)silane, tetra(n-butoxy)silane,tetra(sec-butoxy)silane and tetra(t-butoxy)silane;

trialkoxysilanes such as methyltrimethoxysilane, methyltriethoxysilane,methyltrimethoxyethoxysilane, ethyltriethoxysilane,vinyltrimethoxysilane, phenyltriethoxysilane,γ-chloropropyltrimethoxysilane, γ-chloropropyltriethoxysilane,3,3,3-trifluoropropyltrimethoxysilane, chloromethyltrimethoxysilane,chloromethyltriethoxysilane;

γ-methacryloxypropyltrimethoxysilane, γ-mercaptopropyltrimethoxysilane,γ-rmercaptopropyltriethoxysilane, γ-aminopropyltrimethoxysilane,γ-aminopropyltriethoxysilane,N-β-(aminoethyl)-γ-aminopropyltrimethoxysilane,β-cyanoethyltriethoxysilane;

glycidoxymethyltrimethoxysilane, glycidoxymethyltrimethoxysilane,glycidoxymethyltriethoxysilane, α-glycidoxyethyltrimethoxysilane,α-glycidoxyethyltriethoxysilane, β-glycidoxyethyltrimethoxysilane,β-glycidoxyethyltriethoxysilane, α-glycidoxypropyltrimethoxysilane,α-glycidoxypropyltriethoxysilane, β-glycidoxypropyltrimethoxysilane,β-glycidoxypropyltriethoxysilane;

γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane,γ-glycidoxypropyltripropoxysilane, γ-glycidoxypropyltributoxysilane,γ-glycidoxypropyltrimethoxyethoxysilane,α-glycidoxybutyltrimethoxysilane, α-glycidoxybutyltriethoxysilane,β-glycidoxybutyltrimethoxysilane, β-glycidoxybutyltriethoxysilane,γ-glycidoxybutyltrimethoxysilane, γ-glycidoxybutyltriethoxysilane,δ-glycidoxybutyltrimethoxysilalne, δ-glycidoxybutyltriethoxysilane;

(3,4-epoxycyclohexyl)methyltrimethoxysilane,(3,4-epoxycyclohexyl)methyltrimethoxysilane,β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane,β-(3,4-epoxycyclohexyl)ethyltripropoxysilane,β-(3,4-epoxycyclohexyl)ethyltributoxysilane,β-(3,4-epoxycyclohexyl)ethyltrimethyltrimethoxyethoxysilane;

γ-(3,4-epoxycyclohexyl)propyltrimethoxysilane,γ-(3,4-epoxycyclohexyl)propyltriethoxysilane,δ-(3,4-epoxycyclohexyl)butyltrimethoxysilane andδ-(3,4-epoxycyclohexyl)butyltriethoxysilane;

triacyloxysilanes such as methyltriacetoxysilane, vinyltriacetoxysilane,phenyltriacetoxysilane and γ-chloropropyltriacetoxysilane;

triphenoxysilanes such as methyltriphenoxysilane,γ-glycidoxypropyltriphenoxysilane,β-(3,4-epoxycyclohexyl)ethyltriphenoxysilane;

dialkoxysilanes such as dimethyldimethoxysilane,phenylmethyldimethoxysilane, dimethyldiethoxysilane,phenylmethyldiethoxysilane, γ-chloropropylmethyldimethoxysilane,γ-chloropropylmethyldiethoxysilane,γ-methacryloxypropylmethyldimethoxysilane,methacryloxypropylmethyldiethoxysilane;

γ-mercaptopropylmethyldiiethoxysilane,γ-mercaptopropylmethyldiethoxysilane,γ-iaminopropylmethyldimethoxysilane, γ-aminopropylmethyldiethoxysilane,methylvinyldimethoxysilane, methylvinyldiethoxysi lane;

glycidoxylmethylmethyldimethoxysilane, glycidoxymethylmethyldimethoxysilane, α-glycidoxyethylmethyldimethoxysilane,α-glycidoxyethylmethyldiethoxysilane,β-glycidoxyethylmethyldimethoxysilane,β-glycidoxyethylmethyldiethoxysilane,α-glycidoxypropylmethyldimethoxysilane,α-glycidoxypropylmethyldiethoxysilane,β-glycidoxypropylmethyldimethoxysilane,β-glycidoxypropylmethyldiethoxysilane;

γ-glycidoxypropylmethyldimethoxysilane,γ-glycidoxypropylmethyldiethoxysilane,γ-glycidoxypropylmethyldipropoxysilane,γ-glycidoxypropylmethyldibutoxysilane,γ-glycidoxypropylmethyldimethoxyethoxysilane,γ-glycidoxypropylethyldiethoxysilane,γ-glycidoxypropylethyldipropoxysilane,γ-glycidoxypropylvinyldimethoxysilane,γ-glycidoxypropylvinyldiethoxysilane andγ-glycidoxypropylphenyldiethoxysilane; and

diphenoxysilanes such as dimethyldiacetoxysilane andγ-glycidoxypropylmethyldiphenoxysilane.

As compound 3, those wherein d+e+f=0, particularly tetraalkoxysilanes[Si(OR)₄] and tetraisocyanatosilanes [Si(NCO)₄], are preferable.

Compound 3 may used as such or in the form of a partial hydrolysate. Intreatment of a substrate having functional groups with the composition,it is preferred to chemically bond the partial hydrolysate of compound 1to the functional groups on the substrate surface. A partial hydrolysateof compound 1 usually has residual intact X¹ which shows high reactivityat room temperature. Therefore, the partial hydrolysate can bechemically bound without special treatment.

The water and oil repellent composition of the present invention can beapplied by conventionally known coating methods such as spin coating,dip coating, various types of print coating, spray coating, brushcoating, flow coating, hand coating and squeegee coating. These methodsmay also be employed for pretreatment.

After having been applied, the composition is dried. The drying may benatural drying. Namely, when dried at ordinary temperatures of aboutfrom 0° C. to 50° C., the composition of the present invention can workwell. However, heat may be applied to increase the drying rate or imparthigh durability. Heat drying is preferably done at 50° C. to 40° C.,particularly at 80° C. to 400° C. for from 5 to 30 minutes. Dryingconditions are determined in view of what to be treated and economy.

Concerning application of the composition, it is effective to bring asubstrate having a surface treated with the composition (hereinafterreferred to as a treated substrate) into contact with various solvents.Contact with a solvent is preferable because it removes residual intactreactants on the surface to improve the waterdrop rolling property andprevents poor appearance due to uneven treatment. The solvent which isbrought into contact with a treated substrate is preferably selectedfrom the above-mentioned organic solvents which may be incorporated inthe composition and preferably an organic solvent, if any, contained inthe composition. An appropriate organic solvent may be selected in viewof the work environment, working efficiency, economy and solvency.

Contact between a treated substrate and a solvent may be effected, forexample, by wiping with appropriate cloth or tissue paper impregnatedwith the solvent, spreading drops of the solvent on the treatedsubstrate with tissue paper or the like, soaking the treated substratein a bath of the solvent or spraying the solvent onto the treatedsubstrate.

The thickness of the resulting coating is preferably from the thicknessof a monomolecular film to 0.1 μm because too thick a coatingproblematically accentuates defects or is uneconomical. The thickness ofa coating can be suitably controlled by the treating method, theconcentration of the composition and the drying conditions.

A treated substrate having been treated with the composition of thepresent invention is preferably a substrate made of a transparentmaterial such as glass. A treated substrate may be used for variouspurposes by itself as an article or after incorporated in anotherarticle.

The article may be composed of a treated substrate alone or may be anarticle which incorporates a treated substrate. For example, it may be aglass substrate having a treated surface as an automobile windshield ora mirror incorporating a glass having a treated surface as an automobilerearview mirror part.

Other preferable articles incorporating treated substrates areequipments for transports. As transports, electric railcars, buses,trucks, automobiles, ships and aircrafts may be mentioned. As equipmentsfor transports, exterior parts such as windowpanes, mirrors, CCD lensesand surface panels of display signs and interior parts such as surfacepanels of measuring instruments incorporated in transports, othertransport equipments to use or in use for transports and otherconstituting parts of transports may be mentioned. More specifically,bodies, windowpanes and pantographs of electric railcars, bodies, frontwindshields, side windshields, rear windshields, mirrors and bumpers ofautomobiles, buses and trucks and bodies and windowpanes of ships andaircrafts may be mentioned.

The treated substrate of the present invention or an articleincorporating it has a water-repellent surface, and therefore waterdeposited thereon forms waterdrops. Further, by virtue of its excellentwaterdrop rolling property, when the article is used for a transport, itis possible to prevent waterdrops from staying on the surface becausewaterdrops rapidly rolls on the surface of the article as the transportmoves due to the wind pressure they receive. Thus, it is possible toeliminate adverse effects of water on the surface of the article. Thus,when the article is a see-through part such as a windshield, it ispossible to secure visibility and therefore safe operation. Anotheradvantage of the excellent waterdrop rolling property imparted to thesurface of a treated substrate is that waterdrops are drained from thetreated substrate even when the transport is moving at such a low speedthat barely generates wind pressure or standing.

Further, the treated substrate of the present invention hardly ices upeven under an environment where waterdrops on the surface otherwisefreeze, and has an advantage that even if icing occurs, it can bedefrosted quite quickly. Further, because deposition of waterdrops canbe prevented, it requires less frequent cleaning operations. Further,because the surface of the treated substrate also has an antifoulingproperty, it is advantageous to keep good appearance.

The mechanism of the excellent performance of the surface treatmentagent of the present invention has not been fully elucidated but ispresumed as follows.

A partial hydrolysate of compound 1 in the present invention usually hasboth the hydrophobic R^(f) groups and the hydrophilic groups (X¹) whichremain intact after hydrolysis. In order for the composition havingthese groups to show a good waterdrop rolling property when applied to asubstrate, it is important to align the R^(f) groups outside whileminimizing X¹ on the surface.

If the X¹ groups form chemical bonds with groups on the surface of thesubstrate such as hydroxyl groups on a glass surface, there is nopossibility of X¹ aligned on the surface. However, when the surfacetreatment agent is actually applied, not all the X¹ groups react withgroups on the substrate surface. In such a case, the R^(f) groups in thepartial hydrolysate somewhat align on the surface but randomly, andsupposedly, the surface treatment agent can not work satisfactorilywell. Residual intact X¹ on the coating surface is supposed to act todeteriorate the waterdrop rolling property.

Any molecules of the partial hydrolysate in the present invention fallwithin a molecular weight range of from 2 M to 6 M. Molecules of thepartial hydrolysate having relatively high molecular weights areadvantageous because they have a large number of X¹ which tend to belocated inside. In addition, supposedly, molecules with higher molecularweights have lower degrees of freedom in their molecular motion and aremore likely to settle down to an energetically stable conformation withthe R^(f) groups aligned on the surface to impart a good waterdroprolling property. Decrease of molecules with relatively low molecularweights in the partial hydrolysate likely contributes to improvement ofthe coating durability.

EXAMPLES

Now, the present invention will be described with reference to Examples.Various evaluations in the Examples were done by the following methods.

1. Evaluation of Water Repellency

The contact angle of water was measured.

2. Evaluation of the Waterdrop Rolling Property

On a sample substrate which was held horizontally (at an angle 0°), 50μl of water were dropped in droplets, and the sample substrate wasinclined. The angle between the substrate and a horizontal plane atwhich the water droplets started to roll was read.

3. Evaluation of the Waterdrop Holding Property

Water was sprayed over the entire surface of a vertically standingsample from a nozzle held at a distance of 20 cm from the sample for 1hour, and the waterdrops remaining on the sample surface were observedwith the naked eye and evaluated under the following standard.

A: No waterdrops remain on the sample surface.

B: Waterdrops remain on more than 0% to 30% of the sample surface.

C: Waterdrops remain on more than 30% to 70% of the sample surface.

D: Waterdrops spread over more than 70% of the sample surface.

4. Evaluation of Durability

The water repellency, waterdrop rolling property and water holdingproperty were evaluated after 6 hours of immersion in boiling water.

5. Evaluation of Workability

15 cc of a water and oil repellent composition was dropped onto thesurface of an abrasively cleansed glass substrate (100 cm×100 cm) andspread with tissue paper like car waxing. The workability during thespread was evaluated under the following standard.

∘: The spread took 5 minutes or less.

Δ: The spread took more than 5 minutes but less than minutes.

X: The spread took 15 minutes or more.

6. Method for Molecular Weight Measurement

Instrument: HLC8020 (TOSOH CORPORATION)

Columns: TSKgel G4000HXL for the molecular weight range of from 1000 to100000 TSKgel G2000HXL for the molecular weight range of from 100 to10000

Eluent: Tetrahydrofuran

Flow rate: 0.8 ml/min

Detector: RI

Injection volume: 20 μl

Inlet temperature: 35° C.

Column temperature: 40° C.

Detector temperature: 35° C.

Calibration curve: expressed as polystyrene

Compounds used in the Examples

Compound 1a: CF₃(CF₂)₇(CH₂)₂Si(OCH₃)₃,

Compound 1b: a mixture of CF₃(CF₂)_(n)(CH₂)₂Si(OCH₃)₃ wherein n is 5, 7,9 and 11 and averages 8.

Compound 1c: CF₃(CF₂)₇(CH₂)₃Si(OCH₃)₃,

Compound 1d: CF₃(CF₂)₂OCF(CF₃)CF₂OCF(CF₃)CONH(CH₂)₃Si(OCH₃)3,

Compound 1e: CF₃(CF₂)₇(CH₂)₂OCO(CH₂)₂S(CH₂)₃Si(OCH₃)₃,

Compound 3a: Si(NCO)₄,

Compound 3b: Si(OCH₂CH₃)₄.

Example 1

94.64 g of 2-propanol and 3.41 g of Compound 1a were stirred in a glassreactor equipped with a thermometer and a stirrer at 25° C. for 10minutes, and then 1.95 g of 0.6 wt % aqueous nitric acid was graduallyadded dropwise. 10 days of continuous stirring at 25° C. after thedropwise addition afforded water and oil repellent composition 1. Thehydrolysis conditions and the results of measurement of the molecularweight of the product are shown in Table 1.

In Table 1, the molar ratio of water is the ratio of water in aqueousnitric acid to the total moles of —OCH₃ in the compound prior to thehydrolysis, and the amounts of water and nitric acid are expressed astheir proportions (unit: wt %) in the composition. T₁ and T₂ are thesame as defined previously, and M_(w) is the weight-average molecularweight.

2 cc of 60 wt % cerium oxide aqueous solution was dropped onto thesurface of a soda lime glass plate of 10 cm×10 cm in size (thickness 3.5mm), and the glass plate was abraded with a sponge elaborately. Afterthe abrasion, the cerium oxide was washed away with water, and the glassplate was dried in air at 30° C. Then, 1 cc of the water and oilrepellent composition was dropped onto the surface of the soda limeglass plate and spread with tissue paper like car waxing and dried inthe atmosphere to give sample substrate 1. The results of evaluation ofsample substrate 1 are shown in Table 2.

Example 2

The same reaction as in Example 1 was conducted except that the dropwiseaddition of aqueous nitric acid was followed by 10 days of continuousstirring at 50° C. to give water and oil repellent composition 2. Theresulting composition was applied in the same manner as in Example 1 togive sample substrate 2. The hydrolysis conditions and the results ofmolecular weight measurement are shown in Table 1, and the results ofevaluation of sample substrate 2 are shown in Table 2.

Example 3

95.61 g of 2-propanol and 3.41 g of Compound 1a were stirred in a glassreactor equipped with a thermometer and a stirrer at 25° C. for 10minutes, and then 0.97 g of 0.6 wt % aqueous nitric acid was graduallyadded dropwise. 10 days of continuous stirring at 25° C. after thedropwise addition afforded water and oil repellent 3. The composition 3was applied in the same manner as in Example 1 to give sample substrate3. The hydrolysis conditions and the results of molecular weightmeasurement are shown in Table 1, and the results of evaluation ofsample substrate 3 are shown in Table 2.

Example 4

90.09 g of 2-propanol and 3.41 g of Compound 1a were stirred in a glassreactor equipped with a thermometer and a stirrer at 25° C. for 10minutes, and then 6.49 g of 0.6 wt % aqueous nitric acid was graduallyadded dropwise. 10 days of continuous stirring at 25° C. after thedropwise addition afforded water and oil repellent composition 4. Thecomposition 4 was applied in the same manner as in Example 1 to givesample substrate 4. The hydrolysis conditions and the results ofmolecular weight measurement are shown in Table 1, and the results ofevaluation of sample substrate 4 are shown in Table 2.

Example 5

15 95.74 g of 2-propanol and 3.38 g of Compound 1b were stirred in aglass reactor equipped with a thermometer and a stirrer at 25° C. for 10minutes, and then 0.89 g of 0.6 wt % aqueous nitric acid was graduallyadded dropwise. 10 days of continuous stirring at 25° C. after thedropwise addition afforded water and oil repellent composition 5. Thecomposition 5 was applied in the same manner as in Example 1 to givesample substrate 5. The hydrolysis conditions and the results ofmolecular weight measurement are shown in Table 1, and the results ofevaluation of sample substrate 5 are shown in Table 2.

Example 6

95.67 g of 2-propanol and 3.38 g of Compound 1c were stirred in a glassreactor equipped with a thermometer and a stirrer at 25° C. for 10minutes, and then 0.95 g of 0.6 wt % aqueous nitric acid was graduallyadded dropwise. 10 days of continuous stirring at 25° C. after thedropwise addition afforded water and oil repellent composition 6. Thecomposition 6 was applied in the same manner as in Example 1 to givesample substrate 6. The hydrolysis conditions and the results ofmolecular weight measurement are shown in Table 1, and the results ofevaluation of sample substrate 6 are shown in Table 2.

Example 7

95.81 g of 2-propanol and 3.36 g of Compound 1d were stirred in a glassreactor equipped with a thermometer and a stirrer at 25° C. for 10minutes, and then 0.84 g of 0.6 wt % aqueous nitric acid was graduallyadded dropwise. 10 days of continuous stirring at 25° C. after thedropwise addition afforded water and oil repellent composition 7. Thecomposition 7 was applied in the same manner as in Example 1 to givesample substrate 7. The hydrolysis conditions and the results ofmolecular weight measurement are shown in Table 1, and the results ofevaluation of sample substrate 7 are shown in Table 2.

Example 8

95.92 g of 2-propanol and 3.32 g of Compound 1e were stirred in a glassreactor equipped with a thermometer and a stirrer at 25° C. for 10minutes, and then 0.76 g of 0.6 wt % aqueous nitric acid was graduallyadded dropwise. days of continuous stirring at 25° C. after the dropwiseaddition afforded water and oil repellent composition 8. The composition8 was applied in the same manner as in Example 1 to give samplesubstrate 8. The hydrolysis conditions and the results of molecularweight measurement are shown in Table 1, and the results of evaluationof sample substrate 8 are shown in Table 2.

Example 9

The composition obtained in Example 1 was kept in an atmosphere with ahumidity of 40% and a temperature of 20° for 120 days to givecomposition 9. The composition 9 was applied in the same manner as inExample 1 to give 3 sample substrate 9. The results of molecular weightmeasurement are shown in Table 1, and the results of evaluation ofsample substrate 9 are shown in Table 2.

Comparative Example 1

The same reaction as in Example 1 was conducted except that the dropwiseaddition of aqueous nitric acid was followed by 1 day of continuousstirring at 25° C. to give water and oil repellent composition 11. Thecomposition 11 was applied in the same manner as in Example 1 to givesample substrate 11. The hydrolysis conditions and the results ofmolecular weight measurement are shown in Table 1, and the results ofevaluation of sample substrate 11 are shown in Table 2.

Comparative Example 2

The same reaction as in Example 1 was conducted except that 2-propanolwas used in an amount of 96.26 g, and 0.6 wt % aqueous nitric acid wasadded dropwise in an amount of 0.33 g to give water and oil repellentcomposition 12. The composition 12 was applied in the same manner as inExample 1 to give sample substrate 12. The hydrolysis conditions and theresults of molecular weight measurement are shown in Table 1, and theresults of evaluation of sample substrate 12 are shown in Table 2.

Comparative Example 3

The same reaction as in Example 1 was conducted except that 1.95 g of9.4 wt % aqueous nitric acid was used instead of 0.6 wt % aqueous nitricacid to give water and oil repellent composition 13. The composition 13was applied in the same manner as in Example 1 to give sample substrate13. The hydrolysis conditions and the results of molecular weightmeasurement are shown in Table 1, and the results of evaluation ofsample substrate 13 are shown in Table 2.

Comparative Example 4

Composition 14 prepared by dissolving 3.41 g of compound la in 96.26 gof 2-propanol was applied in the same manner as in Example 1 to givesample substrate 14. The results of evaluation of sample substrate 14are shown in Table 2.

Comparative Example 5

Composition 13 obtained in Comparative Example 3 was kept in anatmosphere with a humidity of 40% and a temperature of 20° C. for 300days to give composition 15. Composition 15 contained a gel-likeprecipitate formed therein and was unable to be applied to a substrate.

TABLE 1 Molar Amount ratio Amount of of of nitric Example Compositionwater water acid T₁ T₂ M_(w) Example 1 1 6 1.936 0.012 56 0 1073(1.9M)Example 2 2 6 1.936 0.012 34 0 1294(2.3M) Example 3 3 3 0.964 0.010 65 0 972(1.8M) Example 4 4 3 6.493 0.065  4 4 1796(3.2M) Example 5 5 3 0.8760.009 62 0 1030(1.8M) Example 6 6 3 0.942 0.010 59 0 1089(1.9M) Example7 7 3 0.827 0.008 57 0 1191(1.8M) Example 8 8 3 0.753 0.007 60 01400(1.9M) Example 9 9 6 1.936 0.012 12 0 1544(2.7M) Comparative 11  61.936 0.012 81 0  888(1.4M) Example 1 Comparative 12  1 0.321 0.003 95 0 761(1.3M) Example 2 Comparative 13  3 1.767 0.183  1 21  2168(3.8M)Example 3

TABLE 2 Initial After durability test Waterdrop Waterdrop WaterWaterdrop Sample Water rolling holding Water dripping holding Work-Example substrate repellency property property repellency propertyproperty ability Ex. 1 1 108 16 A 102 20 A ∘ Ex. 2 2 108 17 A 101 21 A ∘Ex. 3 3 108 18 A  94 29 B ∘ Ex. 4 4 108 18 A  91 27 B Δ Ex. 5 5 109 17 A 96 29 B ∘ Ex. 6 6 108 17 A 102 21 A ∘ Ex. 7 7 106 19 A  99 24 A ∘ Ex. 88 109 18 A  97 25 A ∘ Ex. 9 9 108 17 A 100 21 A ∘ Comp. 11  108 24 A  8146 C ∘ Ex. 1 Comp. 12  106 26 A  82 41 C Δ Ex. 2 Comp. 13  108 20 A  8535 B Δ Ex. 3 Comp. 14   76 35 C  23 — D ∘ Ex. 4

[Examples 10 To 12] Evaluation of Chemical Resistance

Sample substrates 1 [Example 10], sample substrate 2 [Example 11] andsample substrate 5 [Example 12] prepared as described above wereimmersed in the chemicals shown in Table 4 for 24 hours. After theimmersion, the water repellency, waterdrop rolling property andwaterdrop holding property of the sample substrates were evaluated. Theresults are shown in Table 3.

TABLE 3 Waterdrop Waterdrop Sample Water rolling draining Examplesubstrate Chemicals repellency property property 10 1 Methanol 106° 18°A Acetone 107° 19° A 1% 107° 18° A Aqueous Sulfuric acid 1% 104° 21° AAqueous NaOH 11 2 Methanol 107° 18° A Acetone 107° 19° A 1% 107° 19° AAqueous sulfuric acid 1% 105° 22° A Aqueous NaOH 12 3 Methanol 109° 18°A Acetone 107° 17° A 1% 108° 18° A Aqueous sulfuric acid 1% 105° 21° AAqueous NaOH

[Examples 13 to 15] Evaluation of Abrasion Resistance

Sample substrates 1 [Example 13], sample substrate 2 [Example 14] andsample substrate 5 [Example 15] prepared as described above were abradedwith flannel cloth under a 1 kg load back and forth 1500 times. Theresults of evaluation of the water repellency, waterdrop rollingproperty and waterdrop holding property after the abrasion test areshown in Table 4.

TABLE 4 Waterdrop Waterdrop Sample Water rolling draining Examplesubstrate repellency property property 13 1 104° 17° A 14 2 105° 18° A15 5 104° 19° A

Examples 16 to 18 Evaluation of Heat Resistance

Sample substrates 1 [Example 16], sample substrate 2 [Example 17] andsample substrate 5 [Example 18] prepared as described above were heatedat 200° C. for 30 minutes. The results of evaluation of the waterrepellency, waterdrop rolling property and waterdrop holding propertyafter the heating are shown in Table 5.

Example 19

10 cc of 2-propanol was dropped onto Sample substrate 1 prepared asdescribed above and wiped with tissue paper like car waxing, and thewater repellency, waterdrop rolling property and waterdrop holdingproperty were evaluated. The results are shown in Table 5.

TABLE 5 Initial After durability test Waterdrop Waterdrop WaterdropWaterdrop Sample Water rolling holding Water rolling holding Examplesubstrate repellency property property repellency property property 16 1108 14 A 104 19 A 17 2 108 15 A 103 18 A 18 5 109 14 A 103 18 A 19 1 10612 A 100 16 A

Example 20

99.0 g of butyl acetate and 1.00 g of Compound 3a were stirred in aglass reactor equipped with a thermometer and a stirrer at 25° C. forone day to give pretreatment solution 20. 2 cc of 60 wt % cerium oxideaqueous solution was dropped onto the surface of a soda lime glass plateof 10 cm×10 cm in size (thickness 3.5 mm), and the glass plate wasabraded with a sponge elaborately. After the abrasion, the cerium oxidewas washed away with water, and the glass plate was dried in air at 30°C.

Then, 1 cc of the pretreatment solution 20 was dropped onto the surfaceof the soda lime glass plate and spread with tissue paper like carwaxing, and the glass plate was placed in an environment at 20° C. witha humidity of 50% for 1 hour to give pretreated substrate 20.

The pretreated substrate 20 was treated in the same manner as in Example1 instead of the soda lime glass plate to give sample substrate 20. Theresults of evaluation of sample substrate 20 are shown in Table 6.

Example 21

78.80 g of ethyl alcohol and 10.40 g of Compound 3b were stirred in aglass reactor equipped with a thermometer and a stirrer at 25° C. for 10minutes, and then 10.80 g of 0.6 wt % aqueous nitric acid was graduallyadded dropwise. 1 day of continuous stirring at 25° C. after thedropwise addition afforded pretreatment solution 21.

2 cc of 60 wt % cerium oxide aqueous solution was dropped onto thesurface of a soda lime glass plate of 10 cm×10 cm in size (thickness 3.5mm), and the glass plate was abraded with a sponge elaborately. Afterthe abrasion, the cerium oxide was washed away with water, and the glassplate was dried in air. Then, 1 cc of pretreatment solution 21 wasdropped and spread by spin coating (1000 rpm×10 seconds), and the glassplate was dried at 80° C. for 5 minutes to give pretreated substrate 21.

The pretreated substrate 21 was treated in the same manner as in Example1 instead of the soda lime glass plate to give sample substrate 21. Theresults of evaluation of sample substrate 21 are shown in Table 6.

TABLE 6 Initial After durability test Waterdrop Waterdrop WaterdropWaterdrop Water rolling holding Water rolling holding Example repellencyproperty property repellency property property 20 110 15 A 108 18 A 21111 16 A 108 19 A

Example 22

The water and oil repellent composition 1 obtained in Example 1 wasapplied to the surface of a laminated glass for an automobile frontwindshield, and the laminated glass was fixed to an automobile. Theautomobile was actually used for 3 months, and then the condition of thesurface of the front windshield was observed with the naked eye.

No deposition of dirt or dust or no formation of scale due to depositionof waterdrops during the use was observed, and if any, it could be wipedaway with tissue paper easily. In rain, visibility was secured withoutuse of wipers because waterdrops were repelled on the surface anddissipated rapidly with the aid of the wind pressure they received whenthe automobile was running. When the automobile was standing in rain,clear vision was secured without use of wipers because waterdrops rolleddown gravitationally by virtue of the good waterdrop rolling property.

Further, no icing was observed on the front windshield even during a runin such conditions (−5 to 0 ° C.) that an untreated laminated frontwindshield would be iced due to waterdrops deposited thereon.

Example 23

When the laminated front windshield was changed to side windshields, arear windshield and side mirrors, the same effects as in Example 22 wererecognized.

Example 24

The surface of the front windshield of an automobile which had been usedfor three years was abraded with aqueous cerium oxide, washed with waterand dried. The washed laminated front windshield was treated in the samemanner as in Example 1. The automobile was subjected to a test runsimilar to that in Example 22, and the same effects were recognized.

Effects of the Invention

The surface treatment composition of the present invention impartsexcellent water repellency, antifouling property, waterdrop rollingproperty, chemical resistance, anti-icing property and defrostingproperty to a substrate surface. The composition is also excellent instorage stability. The composition has the following effects on atreated substrate treated with the composition.

(1) It eliminates Adverse effects of water and simplifies cleaningoperation by virtue of the excellent water repellency and waterdroprolling property.

(2) It makes the substrate semipermanently usable by virtue of thelasting functional effects.

(3) It can be used for see-through parts of ships to be exposed toseawater by virtue of the excellent chemical resistance.

(4) It woks well without special pretreatment.

(5) It can show its properties upon treatment at ordinary temperature,and can be applicable to a substrate in use or after use, and thereforeis advantageous environmentally and economically.

What is claimed is:
 1. A surface treatment composition, comprising: apartial hydrolysate of a fluorine-containing reactive silane representedby Formula (1): (R^(f)—Q—)_(a)(R¹)_(b)Si(X¹)_(4−a−b)  Formula (1)wherein R^(f) is a monovalent fluorine-containing C₁₋₃₀ organic group; Qis a single bond or a bivalent linking group; R¹ is a hydrogen atom or amonovalent C₁₋₁₆ organic group; a is 1 or 2; b is 0 or 1, and (a+b) is 1or 2; and X¹ is a hydrolyzable group; wherein a proportion (T₁) of amolecule with a molecular weight of at most 2 M in the partialhydrolysate is less than 70% as calculated from Formula (A), wherein Mis a molecular weight of the fluorine-containing reactive silanemeasured by gel permeation chromatography: T₁(%)=[W ₂ /W ₁]×100  Formula(A); wherein W₁ is a total peak area within a molecular weight range offrom 300 to 100000 on a gel permeation chromatogram of the partialhydrolysate of the fluorine-containing reactive silane; and W₂ is atotal peak area within a molecular weight range of from 300 to 2 M on agel permeation chromatogram of the partial hydrolysate of thefluorine-containing reactive silane; wherein a proportion (T₂) of amolecule with a molecular weight of at least 6 M in the partialhydrolysate is less than 10% as calculated from Formula (B): T₂(%)=[W ₃/W ₁]×100  Formula (B); wherein W₁ is a total peak area within amolecular weight range of from 300 to 100000 on a gel permeationchromatogram of the partial hydrolysate of the fluorine-containingreactive silane; and W₃ is a total peak area within a molecular weightrange of from 6 M to 100000 on a gel permeation chromatogram of thepartial hydrolysate of the fluorine-containing reactive silane; andwherein the partial hydrolysate is obtained by partial hydrolysis of thefluorine-containing reactive silane in the presence of water and nitricacid.
 2. The surface treatment composition according to claim 1, whereinthe weight average molecular weight of the partial hydrolysate is from1.6 M to 3.5 M.
 3. The surface treatment composition according to claim1, wherein X¹ is —OR³; and wherein R³ is a C₁₋₆ alkyl group.
 4. Thesurface treatment composition according to claim 1, which contains from0.005 to 0.100 wt % of nitrate ion.
 5. The surface treatment compositionaccording to claim 1, wherein a ratio of the total number of moles ofwater used for the hydrolysis to the total number of moles of X¹ incompound 1 used for the hydrolysis is from 2 to
 7. 6. The surfacetreatment composition according to claim 1, which contains from 0.5 to 3wt % of water.
 7. A method of surface treatment of glass, comprising:applying the surface treatment composition according to claim 1 to thesurface of a glass substrate.
 8. The method according to claim 7,further comprising: drying said surface treatment composition.
 9. Themethod according to claim 7, further comprising: drying said surfacetreatment composition; and contacting said surface treatment compositionwith a solvent.
 10. The method of surface treatment of glass accordingto claim 8, wherein the surface treatment composition is dried at atemperature of 0° C. to 50° C. after it is applied to the glasssubstrate.
 11. The method of surface treatment of glass according toclaim 8, wherein the surface treatment composition is dried at atemperature of 50° C. to 400° C. after it is applied to the glasssubstrate.
 12. The method of surface treatment of glass according toclaim 8, wherein the surface treatment composition is dried for 5 to 30minutes at a temperature of 80° C. to 400° C. after it is applied to theglass substrate.
 13. The method of surface treatment of glass accordingto claim 8, wherein the glass substrate has an intact glass surface or asurface which has been subjected to pretreatment with a fluorine-freehydrolyzable silane compound or to abrasive cleansing.
 14. A treatedsubstrate, having a surface coating formed by applying the surfacetreatment composition according to claim 1 to the surface of thesubstrate and drying it.
 15. The treated substrate according to claim14, wherein the substrate is a glass substrate.
 16. An article,comprising: the treated substrate according to claim
 14. 17. Anequipment for transports, comprising: the article according to claim 16.18. The surface treatment composition according to claim 1, wherein areaction solution containing said fluorine-containing reactive silane,water and nitric acid is stirred for 10 days to obtain said partialhydrolyzate.
 19. A surface treatment composition, comprising: a partialhydrolysate of a fluorine-containing reactive silane represented byFormula (1): (R^(f)—Q—)_(a)(R¹)_(b)Si(X¹)_(4−a−b)  Formula (1) whereinR^(f) is a monovalent fluorine-containing C₁₋₃₀ organic group; Q is asingle bond or a bivalent linking group; R¹ is a hydrogen atom or amonovalent C₁₋₁₆ organic group; a is 1 or 2; b is 0 or 1, and (a+b) is 1or 2; and X¹ is a hydrolyzable group; wherein a proportion (T₁) of amolecule with a molecular weight of at most 2 M in the partialhydrolysate is less than 70% as calculated from Formula (A), wherein Mis a molecular weight of the fluorine-containing reactive silanemeasured by gel permeation chromatography: T₁(%)=[W ₂ /W ₁]×100  Formula(A); wherein W₁ is a total peak area within a molecular weight range offrom 300 to 100000 on a gel permeation chromatogram of the partialhydrolysate of the fluorine-containing reactive silane; and W₂ is atotal peak area within a molecular weight range of from 300 to 2 M on agel permeation chromatogram of the partial hydrolysate of thefluorine-containing reactive silane; wherein a proportion (T₂) of amolecule with a molecular weight of at least 6 M in the partialhydrolysate is less than 10% as calculated from Formula (B): T₂ (%)=[W ₃/W ₁]×100  Formula (B); wherein W₁ is a total peak area within amolecular weight range of from 300 to 100000 on a gel permeationchromatogram of the partial hydrolysate of the fluorine-containingreactive silane; and W₃ is a total peak area within a molecular weightrange of from 6 M to 100000 on a gel permeation chromatogram of thepartial hydrolysate of the fluorine-containing reactive silane; andwherein the partial hydrolysate is obtained by partial hydrolysis of thefluorine-containing reactive silane in the presence of water and nitricacid at a temperature of 25° C.
 20. A surface treatment composition,consisting of: a partial hydrolysate of a fluorine-containing reactivesilane represented by Formula (1):(R^(f)—Q—)_(a)(R¹)_(b)Si(X¹)_(4−a−b)  Formula (1) wherein R^(f) is amonovalent fluorine-containing C₁₋₃₀ organic group; Q is a single bondor a bivalent linking group; R¹ is a hydrogen atom or a monovalent C₁₋₁₆organic group; a is 1 or 2; b is 0 or 1, and (a+b) is 1 or 2; and X¹ isa hydrolyzable group; wherein a proportion (T₁) of a molecule with amolecular weight of at most 2 M in the partial hydrolysate is less than70% as calculated from Formula (A), wherein M is a molecular weight ofthe fluorine-containing reactive silane measured by gel permeationchromatography: T₁(%)=[W ₂ /W ₁]×100  Formula (A); wherein W₁ is a totalpeak area within a molecular weight range of from 300 to 100000 on a gelpermeation chromatogram of the partial hydrolysate of thefluorine-containing reactive silane; and W₂ is a total peak area withina molecular weight range of from 300 to 2 M on a gel permeationchromatogram of the partial hydrolysate of the fluorine-containingreactive silane; wherein a proportion (T₂) of a molecule with amolecular weight of at least 6 M in the partial hydrolysate is less than10% as calculated from Formula (B): T₂(%)=[W ₃ /W ₁]×100  Formula (B);wherein W₁ is a total peak area within a molecular weight range of from300 to 100000 on a gel permeation chromatogram of the partialhydrolysate of the fluorine-containing reactive silane; and W₃ is atotal peak area within a molecular weight range of from 6 M to 100000 ona gel permeation chromatogram of the partial hydrolysate of thefluorine-containing reactive silane; and wherein the partial hydrolysateis obtained by partial hydrolysis of the fluorine-containing reactivesilane in the presence of water and nitric acid.
 21. A surface treatmentcomposition, comprising: a partial hydrolysate of a fluorine-containingreactive silane represented by Formula (1):(R^(f)—Q—)_(a)(R¹)_(b)Si(X¹)_(4−a−b)  Formula (1) wherein R^(f) is amonovalent fluorine-containing C₁₋₃₀ organic group; Q is a single bondor a bivalent linking group; R¹ is a hydrogen atom or a monovalent C₁₋₁₆organic group; a is 1 or 2; b is 0 or 1, and (a+b) is 1 or 2; and X¹ isa hydrolyzable group; wherein a proportion (T₁) of a molecule with amolecular weight of at most 2 M in the partial hydrolysate is less than70% as calculated from Formula (A), wherein M is a molecular weight ofthe fluorine-containing reactive silane measured by gel permeationchromatography: T₁(%)=[W ₂ /W ₁]×100  Formula (A); wherein W₁ is a totalpeak area within a molecular weight range of from 300 to 100000 on a gelpermeation chromatogram of the partial hydrolysate of thefluorine-containing reactive silane; and W₂ is a total peak area withina molecular weight range of from 300 to 2 M on a gel permeationchromatogram of the partial hydrolysate of the fluorine-containingreactive silane; wherein a proportion (T₂) of a molecule with amolecular weight of at least 6 M in the partial hydrolysate is less than10% as calculated from Formula (B): T₂(%)=[W ₃ /W ₁]×100  Formula (B);wherein W₁ is a total peak area within a molecular weight range of from300 to 100000 on a gel permeation chromatogram of the partialhydrolysate of the fluorine-containing reactive silane; and W₃ is atotal peak area within a molecular weight range of from 6 M to 100000 ona gel permeation chromatogram of the partial hydrolysate of thefluorine-containing reactive silane; and wherein the partial hydrolysateis obtained by partial hydrolysis of the fluorine-containing reactivesilane in the presence of aqueous nitric acid and an organic solvent.22. The surface treatment composition according to claim 21, wherein theorganic solvent is present in such an amount that a concentration of thecompound of formula (1) is 0.1-10 wt % based on total weight of thesurface treatment composition.
 23. The surface treatment compositionaccording to claim 22, wherein the organic solvent is a lower alcohol.24. The surface treatment composition according to claim 1, whichcontains from 0.005 to 0.100 wt % of nitrate ion, from 0.5 to 3 wt % ofwater, and an organic solvent in such an amount that a concentration ofthe compound of formula (1) is 0.1-10 wt % based on total weight of thesurface treatment composition.
 25. The surface treatment compositionaccording to claim 1, wherein the partial hydrolyzate is the product ofco-hydrolysis of said silane of Formula (1) and at least one othersilane represented by Formula (2): (R^(f)—Q—)(R¹)(R²)Si(X¹)  Formula (2)wherein R^(f), Q, R¹ and X¹ are as defined above, and R² is a hydrogenor a monovalent C₁₋₁₆ organic group.